Shot peening includes impacting (e.g., shooting, bombarding) a surface of a metallic material with pellets of metal or glass to modify mechanical properties of the material. Shot peening can be used to increase residual stresses of the material, thereby improving the response of the material to, for instance, fatigue.
The figures are not to scale. Instead, the thickness of the layers or regions may be enlarged in the drawings. In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts.